Windows 95/98 HotKey problem

I have been having an intermittent problem on various machines both in Win95 & Win98 where the user is working in an application and for some reason when they press the letter 'E', Windows Explorer comes up. It seems as if Windows thinks that the Windows HotKey is pressed down because when the letter 'R' is pressed, the Run Command box comes up, when the letter 'F' is pressed, the Find box comes up and many other ones. If I press the Windows HotKey to bring up the start menu, then press 'Esc',or if I use Alt+Tab to task to another application it will release the keys back to their normal function. Other times I have to logout and log back in. Would this have anything to do with running a DOS application within Windows? Does anyone know what might cause this, or what a solution could be? Thanks.